Process for forming a photographic image

ABSTRACT

A color photographic material comprising at least one layer of a photographic emulsion is exposed to an image. The exposed material is treated with a color developing solution. The photographic emulsion or developing solution contains a color coupler. The color coupler has the general formula   GROUP, OR IS AN ARALKYL GROUP OR A GROUP, WHERE Y and Z individually mean hydrogen atoms, halogen atoms, lower alkyl groups, lower alkoxy groups, -NHCOR&#39;&#39; groups or -COOR&#39;&#39;&#39;&#39; groups, and X and Z cannot be -NHCOR&#39;&#39; groups at the same time; and each of R5, R6 and R7 is hydrogen atom or an alkyl group having one to 18 carbon atoms. Magenta colored photographic images are obtained which are less absorbing of light in the blue region and exhibit no loss of sensitivity.

United States Patent Iwama et al.

[ Mar. 14, 1972 [54] PROCESS FOR FORMING A PHOTOGRAPHIC IMAGE [72] Inventors: Masakuni Iwama; Tamotsu Kojima; Mitsuto Fuiiwhara; Kenro Sakamoto, all of Tokyo, Japan [73] Assignee: Konishiroku Photo Industry Co., Ltd.

[22] Filed: Oct. 22, 1968 [21] Appl. No.: 769,700

Primary ExaminerWilliam D Martin Assistant ExaminerHarry J. Gwinnell Att0meyl-1arry C. Bierman, Jordan B. Bierman and Bierman & Bierman ABSTRACT A color photographic material comprising at least one layer of aphotographic emplsion is exposed to an :miage Theexposed material is treated with a color developing solution. The photographic emulsion or developing solution contains a color coupler. The color coupler has the general formula wherein R, to R individually mean hydrogen atoms, halogen atoms, lower alkyl groups, lower alkoxy groups, aryl groups, sulfonic groups, sulfonate groups, sulfamide groups, -NHCOR groups or COOR" groups; X is hydrogen atom, a halogen atom, sulfonic group, a sulfonate group or an arylazo group; each of R, R and R" is an aliphatic hydrocarbon radical having up to 20 carbon atoms which may be substituted in the aor B-position of the carbonyl group thereof with sulfonic group, a sulsrmtgrs san a y group or a group, where Y and Z indi v idually mean hydrogen atoms,

halogen atoms, lower alkyl groups, lower alkoxy groups, NHCOR groups or COOR" groups, and X and Z cannot be -NHCOR' groups at the same time; and each of R R and R is hydrogen atom or an alkyl group having one to 18 carbon atomsfMagenta colored photographic images are obtained which are less absorbing of light in the V 1 blue regipn and exhibitno loss of sensitivity.

PROCESS FOR FORMING A PHOTOGRAPHIC IMAGE This invention relates to certain 2-acylaminopyrazolo-[ 1,5- a]-benzimidazole. Further this invention relates to a process for forming a colored photographic image, characterized by using the 2-acylaminopyrazolo-[ l,5-a]-benzimidazole as a color coupler.

As Magenta couplers for color-photographic image formation according to subtractive color method, there have been known yrazolo-l l,5-a]-benzimidazoles disclosed in German Pat. No. 1,070,030 and Japanese Patent No. 9,353/1966. These couplers are more excellent than those which were known heretofore in that Magenta dyes obtained by coupling with oxidized paraphenylenediamine-type color-developer have no secondary absorption in the blue region. However, Magenta dyes derived from the above-mentioned Magenta couplers suffer from such drawbacks that they still have substantial light absorptions in the blue region, and that when incorporated into photographic emulsions, they are greatly lowered in sensitivity as compared with the conventional 5- pyrazolones to make it difficult to attain a required maximum density.

Light absorptions in the blue region of the Magenta dyes have such detrimental effects on the lights in the blue region as, for example, to degrade the saturation of color images and to bring about the turbidity of colors. In the case of Magenta dyes, therefore, the smaller the light absorptions in the blue region, the more preferable from the photographic standpoint. Further, it is not desirable to use as couplers those which, when added to photographic emulsions, bring about the degradation in sensitivity and the like characteristics of the emulsions.

An object of the present invention is to provide certain new 2-acylamino-pyrazolo-[l,5-a]-benzimidazoles. Another object of the invention is to provide a process for forming a colored photographic image in which a Magenta colored photographic image less in light absorption in the blue region is formed without any adverse influence on the sensitivity of photographic emulsion or a required maximum density.

In the particular aspect of this invention, a novel compound represented by the general formula group, where Y and Z are hydrogen atoms, halogen atoms,

lower alkyl group, lower alkoxy group, NHCOR groups or COOR" groups, and Y and 2 cannot be NHCOR groups at a same time; and R R and R are hydrogen atoms or alkyl 5 groups having one to l8 carbon atoms, is incorporated as a color coupler into a silver halide emulsion according to a known procedure, and is applied onto a suitable support such as a film base, followed by drying, to prepare a photographic material. Subsequently, the material is subjected to imagewise exposure, and is then developed by means of a paraphenylenediamine-type color developer to form a Magenta color photographic image. Alternatively a black and white photographic film, which has been exposed imagewise is treated in a color developing solution containing a novel coupler compound of the above-mentioned general formula thereby to form a Magenta color photographic image.

The thus formed Magenta color photographic image has its maximum absorption in the green region, and is higher in maximum density and far lower in light absorption in the blue region than a Magenta color photographic image derived from a known pyrazolo-[ l,,5-a]-benzimidazole.

Typical examples of the compounds represented by the aforesaid general formula are shown below, but compounds usable in the present invention are not limited only to these.

(l) 2-acetamlno-pyrazolo-1,fi-a-benzlmldazole C C Hz N H O 00 H! N M.P. 290-295 C.

(2) Dlsodlum 2-acetamlno-pyrazo1o-[1,lS-a]benzimidazole-3,6-dlsultonate (6) Z-benzoylamlno-pyrazolo-[1,5e1-benzimidazolo N W OHa N JJ-NHC O 00H;

(6) 2-a-suliopalmltoylanflno-pyrMole-[1,5-a1-benzim1da2ole c-oH, L JZNHCOCHCH|4H20 l N SOQH M.P. 280285 C.

(7) 2-stearoylamlno-6-sulfo-pyrazolo-[1,5-a]-benzimidazole N 7 Es oF M.P. 293-295 C.

M.P. 259260 C M.P. 300-305 C.

(8) .l-palmitoylamino-pyrazolo-[l,5-a1-benzlmidazole CC H2 M.P. 140-143 C.

(9) 2-(2,4-di't-amylphenoxy)-acetamino-fi-methoxy-pyrazolo-[l,E-albenzimidazole tCnHu (10) 2-(a-2,4-di-tamlyphenoxy)-acetamino-6,S-dichloro-pymzolo- [1,6-a1-benzlmidazole sHu (12) 2-[3-(B-octadeeylsuccinylamino)-benzoylamtno]-6-rnethoxypyrazolo-[1,5-a]-benztrnldazole C310- ooH,

l I -NHCO NHC CH CHCmHg O OH M.P. 264-267 C.

1-(4-methoxyphenylazo)-2-{a-(2,Ml-t-amylphenoxykbutyroylaminol-pyrazolmll,5-a]-benzlmldazole Generally, the above-mentioned compounds can be synthesized with favorable yields and purity by heating a l-(2- aminophenyl)-3-acylamino-S-pyrazolones in a lower fatty acid (eg, formic, acetic or n-butyric acid) and then, if desired, introducing a desired substituent into the 4-.position of the pyrazolone ring of the resulting cyclization product. Depending on the kind of compounds, the addition of an alkali metal salt of a lower fatty acid (e.g., sodium acetate) is sometimes advantageous. The following examples will illustrate the synthetic procedures for the preparation of some compounds ofthis invention LII EXAMPLE I twenty-three Grams of l-(Z-aminophenyl)-3-acetamino-5- pyrazolone were heated under reflux for 2 hours in 300 cc. of glacial acetic acid and then cooled with water whereupon white crystals were precipitated. The crystals were collected by filtration and recrystallized from acetonitrile toyicld white lumpy crystals (m.p. 293-295 C.; yield 17 g.). The product tyroylamino-S-pyrazolone in place of l-(2-aminophenyl)-3- acetamino-S-pyrazolone used in the foregoing Example 1, 2- butyroylamino-6-methyl-pyrazolo-[ l,5-a]-benzirnidazole in the form of white plate crystals represented by the formula:

1!\ -Nnooclm was obtained. Starting from benzoylamino-S-pyrazolone, 2- benzoylamino-pyrazolo-I l,5-a]-benzimidazole in the form of white needle crystals represented by the formula:

N NHCOCaH5 was obtained Starting from l-(2,4-dichl0ro-6-aminophenyl)- 3-(2,4-di-tert.-amylphenoxyacetamino )-5-pyrazolone and using a m i7 ture o f alcohol and water in place of acetonitrile, 2- (2,4 di tert. amylphenoxyacetylamino) 6,8 -dichloro pyrazolo-[ l,5-a]-benzimidazole in the form of a white solid mass represented by the formula:

41-NHC oomoQ-e-onam \NW was obtained. Similarly, 2-{3-(,B-octadecylsuccinylamino)- benzolyamino} '-methoxy -pyrazolo -{l ,5-a] benzimidazole in the form of white amorphous crystals represented by the formula; A A.

l N\ (LNHC 0-@ COOH was obtained by using l-(2-amino-4-methoxyphenyl)-3-{3- (B-octadecylsuccinylamino) benzoylamino} 5 MEZOIOUC and recrystallizing the product from alcohol. Using l-(2- amino-4-phenyll-phenyl-3 i2;rnethyoxy) :benzoylamino 5- pyrazolone in an analogous manner, 2-(2-methoxybenzoylamino)-6-phenyl-pyrazolo-[ l,5-a]-benzimidazole in the form of white plate crystals represented by the formula:

OCH;

was obtained.

EXAMPLE 2 forty-three Grams of l-(Z-aminophenyl)-3-palmitoylamino- S-pyrazole were heated under reflux for 2 hours with 500 cc. of n-propionic acid and then cooled whereupon crystals were precipitated. The crystals were collected by filtration and recrystallized from acetonitrile to obtain white plate crystals (m.p. l40-143 C.; yield 25 g.).

This product was 2-palmitoylamino-pyrazolo-[ l,5-a]- benzimidazole represented by the formula:

Analysis: C H N c H N Cale. 73.|3 9.33 13.65 Found 7326 9.43 13.37

EXAMPLE 3 In nitrogen atmosphere, 64 g. of triethylamine salt of l-(2- aminophenyl)-3-a-sulfostearoylamino-5-pyrazolone were heated under reflux for 4 hours with 1.5 lofglacial acetic acid. The reaction mixture was cooled to 50 C. and 10 cc. of concentrated hydrochloric acid were added slowly thereto to permit precipitation of white crystals. The precipitate was collected by filtration, washed with glacial acetic acid and then further washed with acetonitrile to obtain white amorphous crystals (m.p. 280-285 C. with decomposition; yield 24 g.).

This product was 2-(a-sulfostearoylamino)-pyrazolo-[1,5- al-benzimidazole represented by the formula:

CCHg IL NHCOCH-Qqfl Analysis: C H 0 N S 8.16 c H N s Culc. 62.5l 10.80 6.18 Found 6237 8.22 10.94 6.33

EXAMPLE 4 38.8 Grams of l-(2-amino-4-sulfophenyl)-3-(4-methylbenzoylamino)-5-pyrazolone were dissolved into 300 cc. of glacial acetic acid containing g. of sodium acetate and the mixture was boiled under reflux for 2 hours. Glacial acetic acid was removed under reduced pressure and after addition of 200 cc. of methanol the reaction mixture was warmed to loosen the crystals. The precipitate was filtered and recrystallized from 70 percent methanol to obtain 24 g. of white lumpy crystals (m.p. above 300 C.

This product was sodium 2-(4-methylbenzoylamino)- pyrazolo-[l,5a]benzimidazole-6-sulfonate represented by the formula:

Analysis: C H 0 N SNa-H 0 C H N S Cale. 49.75 3.68 I165 7.!" Found 49.83 3.7l 13.55 7.76

Using l-(2-amino-4-carboxyphenyl)-3-isonicotinoylamino- S-pyrazolone in place of 1-(2-amino-4-sulfophenyl)-3-(4- methybenzoylamino)-5-pyrazolone referred to in the foregoing example and anhydrous potassium acetate in place of sodium acetate, potassium 2-isonicotinoylamino-pyrazolo-[ l ,S-albenzimidazole-6-carboxylate in the form of white amorphous crystals represented by the formula:

KOOC

' was obtained. In a similar manner using l-(2-chloro-4-carboxy-6-amino)-3-(4-0ctadecylaminosulfonylbenzoylamino-S- pyrazolone, sodium 2- {4-(octadecylaminosulfonyl be zey aminekfi-qhlo -pxrazo 11.sral.:l2nz m 1a;o1:ocarboxylate in the form of white lumpy crystals represented by the formula:

benzimidazole obtained in Example 1 were reacted with 40 ml. of 10 percent oleum at 5l0 C. The reaction mixture was poured into ice and then added with g. of calcium carbonate. The mixture was filtered and the filtrate was dried under reduced pressure. The residue obtained was dissolved in water. The resulting solution was adjusted to pH 6-7 with an aqueous sodium carbonate solution and thereafter heated at .8Q;1. Q Thesolution was filteredan the fi rate wasdl d- The residue was recrystallized from 50 percent ethanol to yield white powdery crystals (m.p. 300 C. (decomp.); yield 1 l g.). The product thus obtained was disodium Z-acetaminopyrazolo-[ l,5-a]benzimidazole-3,-disulfonate. Analysis: C1 1 11 1 4 2 2( 2H20) c n N s Calc. 29.07 2.66 12.33 14.11 Found 29.23 2.62 12.49 14.41

EXAMPLE 6 twenty-five grams of 2-palmitoylamino-6,8-

dichloropyrazolo-[l,5-a]-benzimidazole was reacted with 21 g. of sulfuryl chloride in chloroform at room temperature. The reaction mixture was distilled to dryness under reduced pressure. The residue was 2-palmitoylamino-33,6,8- tetrachloropyrazolo-[ l,5-a]-benzimidazole which was then hydrogenated in ethanol with a Raney nickel to obtain Z-palmitoyl-3 ,6,8-trichloropyrazolo l,5-a]-benzimidazole. After recrystallization from methanol, powdery white crystals were obtained (m.p. lO-l05 C.; yield 20 g.) Analysis: C H N OCl c H N Cl Calc. 58.42 6.86 10.90 20.70 Found $8.13 6.67 11.01 20.82

EXAMPLE 7 eitht grams of anisidine were diazotized with dilute hyd ochloric acid and sodium nitrite at a temperature below 5 C. This diazotized solution was added at a temperature below 8 C. to 26 g. of 2-2,4-di-t-amylphenoXy-butyroylamino) pyrazolo [2,4- di ticmylphenoxy bu tyroylamino)-pyrazolo-[l,5 a]-benzimidazole dissolved in 800 ml. Thereafter, the mixture was added with l,500 ml. of water. Yellowish orange precipitates were collected by filtration and recrystallized from ethanol. Yellowish orange powdery crystals were obtained (m.p. 171-l73C.; yield 22 g.). The product obtained was 1-( 4-methoxyphenylazo)-2-[a-(2,4 zi x phsn l b t laminol MQQ Q [Liaibenzimidazole. Analysis: C H N 0 C H N Calc. 7|.02 7.29 13.81 Found 7128 7.40 14.01

When the above-mentioned compounds are used in greensensitive layers of multilayer-type color photographic materials, there are obtained color images excellent in color reproductivity. Accordingly, the above compounds are particularly advantageous for the preparation of positive photographic materials. Furthermore, the resulting materials are more excellent in color sensitivity and are particularly useful as high-speed photographic materials.

The present invention is further illustrated below with reference to examples, which will serve to understand utility of the compounds of the invention as color couplers.

EXAMPLE 8 twenty grams of the compound exemplified by (6), i.e., 2-asulfopalmitoylamino-pyrazolo-[ 1,5-a]-benzimidazole, was dissolved in 60 ml. of a l N-aqueous caustic potash solution. To the solution, water was added to make 200 ml. Subsequently, the solution was added to and dispersed in 1 kg. of a high speed green-sensitive silver iodobromide emulsion. The thus formed dispersion was adjusted to pH 6.9 with citric acid, was applied onto a film base according to an ordinary procedure, and was then dried.

Subsequently, the film was exposed and was then developed at 20 C. for 10 minutes in a color developer of the following composition:

N,N-diethylparaphenylenediamine sulfate 2.5 g. Sodium sulfile 2.0 g. Sodium carbonate (monohydrate) 82.0 g. Potassium bromide g. Water to make 1000 ml.

Further, the film was treated with a stop solution and then with a fixing solution according to ordinary procedures, was washed with water for 10-20 minutes, and was then treated for 5 minutes in a bleaching bath of the following composition:

Potassium ferricyanide I00 g. Potassium bromide 50 g. Water to make 1000 mlv Thereafter, the bleached film was washed with water for l0 minutes and was further treated for 5 minutes in a treating bath of the following composition:

Sodium thiosulfate Water to make 250 3. I000 ml.

N H038 CH:

which is disclosed in German Pat. No. 1,070,030, was used in place of the said compound exemplified by (6). The known film thus obtained was compared in color density with the film of this example, using blue, green and red filters, to obtain the results set forth in the following table:

ru 6 ir/ I;

Film of this example 0. l 7 0.27 0.43 Known film 022 0.36 0.20

In the above table;

D Blue light density D Green light density.

D, Red light density.

As is clear from the above table, the color image formed in accordance with the present invention is far less in light absorption in the blue and red light areas. It is therefore possible to obtain a clear color photographic image free from turbid color.

EXAMPLE 9 ws y stasis 91. the sqmps isxsmplifisq b (4 i palmitoylamino-2,6,S-trichloro-pyrazolo-I l,5-a]- benzimidazole, was dissolved in 40 g. of dibutyl phthalate. To this solution were added 400 ml. of a 10 percent aqueous gelatine solution and 20 ml. of a 5 percent saponin solution. The mixed solution was subjected to a colloid mill to form an emulsified dispersion. This dispersion was added to 1 kg. of a silver iodobromide emulsion, and the mixture was applied onto a support and was then dried to obtain a photographic material. This material was exposed and was then developed at 20 C. for 10 minutes by use of a developer having the following composition:

Anhydrous sodium sulfite 40.0 g p-N-methylaminophenol sulfate 5.0 g Hydroquinone 2.0 g Sodium carbonate (rnonohydrate) 25.0 3

Potassium bromide 1.0 g. Water to make i000 ml.

N-Ethyl-N-B-methanesulfonamidoethyl-3-methyl-4- aminoaniline (sesqui-sulfate, monohydrate) 5.0 g. Sodium sulfite 2.0 g. Sodium carbonate (monohydrate) 82.0 g. Potassium bromide 2.0 g. Water to make 1000 ml.

The thus developed material was successively subjected, according to ordinary procedures, to stopping, water-washing, bleaching, fixing and water-washing, and was then dried to obtain a Magenta color photographic image having a maximum absorption at 570 my which was excellent both in photographic characteristics and in spectral absorption characteristics.

EXAMPLE 10 A film coated with a layer of a common silver bromide emulsion was exposed and was then treated at 20 C. for 12 minutes with a color developer of the following composition:

N,N-diethylparaphenylenediamine sulfate 6.0 g. Sodium sulfite 2.0 g. Sodium carbonate (monohydrute) 80.0 g. Potassium bromide 10 g. Coupler solution 10 ml. Water to make 1000 ml.

tion characteristics.

What is claimed is:

l. A process for forming a colored photographic image which comprises imagewise exposing a color photographic material comprising at least one layer of a silver halide photographic emulsion and then developing the exposed material with a color developing solution, in the presence of 2-palmitoylamino-Z,6,8-trichloropyrazolo-[ l,5-a]-benzimidazole as a color coupler.

2. The process as claimed in claim 1 wherein said color coupler compound is contained in the photographic emulsion.

3. The process as claimed in claim 1 wherein the color coupler is contained in the color developing solution.

4. A process for forming a colored photographic image which comprises imagewise exposing a color photographic material comprising at least one layer of a silver halide photographic emulsion and then developing the exposed material with a color developing solution in the presence of 2-a-sulfopalmitoylamino-pyrazolo-[ l,5-a]-benzimidazole, as a color coupler.

5. The process as claimed in claim 4 wherein said color coupler compound is contained in the photographic emulsion.

6. The process as claimed in claim 4 wherein the color coupler is contained in the color developing solution.

7. A process for forming a colored photographic image which comprises imagewise exposing a color photographic material comprising at least one layer of a silver halide photographic emulsion and then developing the exposed material with a color developing solution in the presence of 2-(a2,4-dit-amylphenoxy)-acetamino-6,8-dichloropyrazolo-[ 1 5-21]- benzimidazole, as 'a color coupler.

8. The process as claimed in claim 7 wherein said color coupler compound is contained in the photographic emulsion.

9. The process as claimed in claim 7 wherein the color coupler is contained in the color developing solution. 

2. The process as claimed in claim 1 wherein said color coupler compound is contained in the photographic emulsion.
 3. The process as claimed in claim 1 wherein the color coupler is contained in the color developing solution.
 4. A process for forming a colored photographic image which comprises imagewise exposing a color photographic material comprising at least one layer of a silver halide photographic emulsion and then developing the exposed material with a color developing solution in the presence of 2- Alpha -sulfopalmitoylamino-pyrazolo-(1,5-a)-benzimidazole, as a color coupler.
 5. The process as claimed in claim 4 wherein said color coupler compound is contained in the photographic emulsion.
 6. The process as claimed in claim 4 wherein the color coupler is contained in the color developing solution.
 7. A process for forming a colored photographic image which comprises imagewise exposing a color photographic material comprising at least one layer of a silver halide photographic emulsion and then developing the exposed material with a color developing solution in the presence of 2-( Alpha 2,4-di-t-amylphenoxy)-acetamino-6,8-dichloropyrazolo-(1,5-a)-benzimidazole, as a color coupler.
 8. The process as claimed in claim 7 wherein said color coupler compound is contained in the photographic emulsion.
 9. The process as claimed in claim 7 wherein the color coupler is contained in the color developing solution. 